Abstract The objective of this proposal is to develop an effective method for providing a functional cure for HIV- infected individuals. The approach is based on the observation that subjects lacking CCR5 expression can be highly resistant to HIV infection. Our hypothesis is that hematopoietic CD34+ stem and progenitor cells (HSPC) can be made resistant to HIV infection via mutation or deletion in the CCR5 gene. These cells transplanted back to autologous donors will prevent HIV replication and effect a cure. First, purified human CD34+ stem cells or peripheral blood mononuclear cells from uninfected individuals will be converted into induced pluripotent stem (iPS) cells by a variety of strategies with emphasis given to non-integrating vectors. These iPS cells will then be genetically modified to either lack the CCR5 gene or have the natural mutation of CCR5. Cells naturally lacking CCR5 expression were given to the Berlin patient who has no evidence of HIV infection after several years. The iPS-derived CCR5-mutated cells will be differentiated into CD34+ cells (i.e. iPS-derived HSPC) and then differentiated into hematopoietic progeny cells. These cells will be evaluated for normal cell function and resistance to HIV infection in cell culture and after transplantation into humanized mice. The same procedures will be undertaken with CD34+ cells from HIV-infected individuals. These studies are directed at optimizing our approaches for providing iPS-HSPC to HIV-infected individuals to prevent HIV disease progression and potentially establish a functional cure.